The following commit has been merged into the core/rcu branch of tip:
Commit-ID: e3771c850d3b9349b48449c9a91c98944a08650c
Gitweb: https://git.kernel.org/tip/e3771c850d3b9349b48449c9a91c98944a08650c
Author: Frederic Weisbecker <frederic@xxxxxxxxxx>
AuthorDate: Mon, 21 Sep 2020 14:43:40 +02:00
Committer: Paul E. McKenney <paulmck@xxxxxxxxxx>
CommitterDate: Thu, 19 Nov 2020 19:37:16 -08:00
rcu: Implement rcu_segcblist_is_offloaded() config dependent
This commit simplifies the use of the rcu_segcblist_is_offloaded() API so
that its callers no longer need to check the RCU_NOCB_CPU Kconfig option.
Note that rcu_segcblist_is_offloaded() is defined in the header file,
which means that the generated code should be just as efficient as before.
Suggested-by: Paul E. McKenney <paulmck@xxxxxxxxxx>
Signed-off-by: Frederic Weisbecker <frederic@xxxxxxxxxx>
Cc: Paul E. McKenney <paulmck@xxxxxxxxxx>
Cc: Josh Triplett <josh@xxxxxxxxxxxxxxxx>
Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
Cc: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx>
Cc: Lai Jiangshan <jiangshanlai@xxxxxxxxx>
Cc: Joel Fernandes <joel@xxxxxxxxxxxxxxxxx>
Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxx>
---
kernel/rcu/rcu_segcblist.h | 2 +-
kernel/rcu/tree.c | 21 +++++++--------------
2 files changed, 8 insertions(+), 15 deletions(-)
diff --git a/kernel/rcu/rcu_segcblist.h b/kernel/rcu/rcu_segcblist.h
index 5c293af..492262b 100644
--- a/kernel/rcu/rcu_segcblist.h
+++ b/kernel/rcu/rcu_segcblist.h
@@ -62,7 +62,7 @@ static inline bool rcu_segcblist_is_enabled(struct rcu_segcblist *rsclp)
/* Is the specified rcu_segcblist offloaded? */
static inline bool rcu_segcblist_is_offloaded(struct rcu_segcblist *rsclp)
{
- return rsclp->offloaded;
+ return IS_ENABLED(CONFIG_RCU_NOCB_CPU) && rsclp->offloaded;
}
/*
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 93e1808..0ccdca4 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -1603,8 +1603,7 @@ static bool __note_gp_changes(struct rcu_node *rnp, struct rcu_data *rdp)
{
bool ret = false;
bool need_qs;
- const bool offloaded = IS_ENABLED(CONFIG_RCU_NOCB_CPU) &&
- rcu_segcblist_is_offloaded(&rdp->cblist);
+ const bool offloaded = rcu_segcblist_is_offloaded(&rdp->cblist);
raw_lockdep_assert_held_rcu_node(rnp);
@@ -2048,8 +2047,7 @@ static void rcu_gp_cleanup(void)
needgp = true;
}
/* Advance CBs to reduce false positives below. */
- offloaded = IS_ENABLED(CONFIG_RCU_NOCB_CPU) &&
- rcu_segcblist_is_offloaded(&rdp->cblist);
+ offloaded = rcu_segcblist_is_offloaded(&rdp->cblist);
if ((offloaded || !rcu_accelerate_cbs(rnp, rdp)) && needgp) {
WRITE_ONCE(rcu_state.gp_flags, RCU_GP_FLAG_INIT);
WRITE_ONCE(rcu_state.gp_req_activity, jiffies);
@@ -2248,8 +2246,7 @@ rcu_report_qs_rdp(struct rcu_data *rdp)
unsigned long flags;
unsigned long mask;
bool needwake = false;
- const bool offloaded = IS_ENABLED(CONFIG_RCU_NOCB_CPU) &&
- rcu_segcblist_is_offloaded(&rdp->cblist);
+ const bool offloaded = rcu_segcblist_is_offloaded(&rdp->cblist);
struct rcu_node *rnp;
WARN_ON_ONCE(rdp->cpu != smp_processor_id());
@@ -2417,8 +2414,7 @@ static void rcu_do_batch(struct rcu_data *rdp)
{
int div;
unsigned long flags;
- const bool offloaded = IS_ENABLED(CONFIG_RCU_NOCB_CPU) &&
- rcu_segcblist_is_offloaded(&rdp->cblist);
+ const bool offloaded = rcu_segcblist_is_offloaded(&rdp->cblist);
struct rcu_head *rhp;
struct rcu_cblist rcl = RCU_CBLIST_INITIALIZER(rcl);
long bl, count;
@@ -2675,8 +2671,7 @@ static __latent_entropy void rcu_core(void)
unsigned long flags;
struct rcu_data *rdp = raw_cpu_ptr(&rcu_data);
struct rcu_node *rnp = rdp->mynode;
- const bool offloaded = IS_ENABLED(CONFIG_RCU_NOCB_CPU) &&
- rcu_segcblist_is_offloaded(&rdp->cblist);
+ const bool offloaded = rcu_segcblist_is_offloaded(&rdp->cblist);
if (cpu_is_offline(smp_processor_id()))
return;
@@ -2978,8 +2973,7 @@ __call_rcu(struct rcu_head *head, rcu_callback_t func)
rcu_segcblist_n_cbs(&rdp->cblist));
/* Go handle any RCU core processing required. */
- if (IS_ENABLED(CONFIG_RCU_NOCB_CPU) &&
- unlikely(rcu_segcblist_is_offloaded(&rdp->cblist))) {
+ if (unlikely(rcu_segcblist_is_offloaded(&rdp->cblist))) {
__call_rcu_nocb_wake(rdp, was_alldone, flags); /* unlocks */
} else {
__call_rcu_core(rdp, head, flags);
@@ -3712,8 +3706,7 @@ static int rcu_pending(int user)
/* Has RCU gone idle with this CPU needing another grace period? */
if (!gp_in_progress && rcu_segcblist_is_enabled(&rdp->cblist) &&
- (!IS_ENABLED(CONFIG_RCU_NOCB_CPU) ||
- !rcu_segcblist_is_offloaded(&rdp->cblist)) &&
+ !rcu_segcblist_is_offloaded(&rdp->cblist) &&
!rcu_segcblist_restempty(&rdp->cblist, RCU_NEXT_READY_TAIL))
return 1;
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